Background: Nasal saline irrigations (NSIs) are commonplace in treatment of patients with sinonasal disorders. Contamination of both the water source and delivery bottle remains a challenge with this therapy. The goal of this study was to optimize a disinfection technique with various methods of preparation, disinfection, and delivery of NSIs. Methods: Distilled and tap water sources in NSI bottles were contaminated by 4 bacterial strains: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Legionella pneumophila. Contaminated bottles were cleaned with tap water, tap water with detergent, or microwave and swabbed for culture. Water-source disinfection was performed with reverse osmosis, distillation, activated carbon filtration, boiling, or ultraviolet (UV) light treatment. Test samples from each experimental group (n = 3/group) were cultivated on the appropriate media with colony-forming units (CFUs) reported. Results: All methods of bottle cleaning with tap water with/without detergent and microwave significantly reduced bacterial load (CFUs) by >99% (p < 0.05). Distillation and boiling of the contaminated water source eliminated 100% of bacteria, whereas reverse osmosis and activated carbon filtration did not. A single UV treatment of contaminated water within a bottle eliminated 99% of bacteria within the water and 100% in the bottle. Conclusion: Cleansing of NSI bottles with tap water with/without detergent or microwave produced robust bacterial disinfection. Distillation and boiling of a contaminated water source completely eliminated all bacteria. UV light treatment was capable of simultaneous disinfection of both the water source and bottle, suggesting this may be a convenient, 1-step method of preparing NSIs for patients.